The
circuit of graphic equalizer, allocates ten adjusting potesometer , that each one from
them affects in a predetermined area of frequencies, the central frequency of which
abstains a octave (double), from the central frequencies of her neighbouring regions. Each
unit has common materials with remainder and it differs only in the capacity of capacitors
that constitutes the filter in each unit. When the runner of fader regulation RV1 until
RV10, is in the middle then we do not have no intervention of filter above in the signal
that passes from in his and gain of particular unit, is one [ X1 ]. On the contrary if the
runner is moved to a side of exit, the unit acts as filter of cutting off of area and it
degrades the signals of predetermined area of frequencies. On the contrary if it is moved
to the side of entry, the rung acts as filter of passage of area, strengthening the
signals of predetermined area of frequencies. The quality of all materials should be very
good. Specifically potesometer RV1... the 10 and capacitors. If it is intended for stereo
use then it will be supposed it is made in two pieces with as much as possible suited the
materials, between the channels, so that do not exist differences in the regulation of
each band frequencies. Switch S1 isolates the circuit EQ, when him we did not need and it
ensures level [ flat ] response in the exit of circuit. The circuit should be connected
between preamplifier and in a final power amplifier.

Part
List

R1....20= 10Kohms

C4= 10nF polyester

C18= 68pF polysterine

R21....40= 1Mohms

C5= 47nF polyester

C19= 360pF polysterine

R41= 10Kohms

C6= 4.7nF polyester

C20= 36pF polysterine

R42= 1Kohms

C7= 22nF polyester

C21= 4.7uF polyester

R43.....52= 2.2Kohms

C8= 2.2nF polyester

C22-23= 33pF polysterine

R53.....62= 47Kohms

C9= 12nF polyester

C24= 10uF 25V

R63-64-66-67= 47Kohms

C10= 1.2nF polyester

C25-26= 47uF 25V

R65= 10Kohms

C11= 5.6nF polyester

C27...32= 47nF polyester

R68-69= 47 ohms 1/2W

C12= 560pF polysterine

IC1...3=TL074

RV1....10= 100Kohms
lin FADER

C13= 2.7nF polyester

S1= 2X4 SW for stereo

RV11= 10Kohms log.

C14= 270pF polysterine

C1= 180nF polyester

C15= 1.5nF polyester

C2= 18nF polyester

C16= 150pF polysterine

C3= 100nF polyester

C17= 680pF polysterine

]

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